1. Field of the Invention
The present invention is related to a touch panel, and particularly, to a touch liquid crystal display panel.
2. Description of the Prior Art
Portable electronic devices such as PDAs, mobile phones, global positioning systems (GPS), and digital video players generally use a touch panel as the communicating interface between a user and the machine. Modern consumer electronic devices are increasingly smaller and lighter. In order to save space, a touch panel, which inputs data when it is touched, is the key component of modern consumer electronic devices, replacing traditional input devices, such as keyboards and mouse.
Please refer to FIG. 1, which is a schematic diagram showing a conventional touch panel. The conventional touch panel 10 is placed on a display side of a display panel 30. The touch panel 10 has a conductive glass substrate 12, a conductive thin film 14 disposed on the conductive glass substrate 12, and a plurality of spacers 13 positioned between the conductive glass substrate 12 and the conductive thin film 14. A top transparent conductive layer 16 and a bottom transparent conductive layer 18 are respectively positioned on a surface of the conductive glass substrate 12 and a surface of the conductive thin film 14 facing each other. The top transparent conductive layer 16 is electrically connected to a conductive trace 20, and the bottom transparent conductive layer 18 is electrically connected to another conductive trace 22. In addition, the conductive traces 20, 22 are electrically connected to a flexible printed circuit (FPC) 24. The conventional touch panel 10 is a resistance type touch panel, which senses a signal according to a voltage variation. When a finger touches the conductive thin film 14 of the touch panel 10, a voltage variation is induced at the touch point. The position of the touch point may be calculated by the value of the voltage variation, and the input signal representing the touch point is sent out through the bottom transparent conductive layer 16, the conductive trace 22, and the FPC 24.
The above-mentioned conventional touch panel 10 is disposed on the display side of the display panel 30 through an external attachment. The addition of the conventional touch panel 10 increases the thickness of the display panel 30 and reduces the light transmitting rate. Therefore, the brightness of the display panel is reduced. In addition, the conventional touch panel 10 only supports a single touch input, which means only one point may be used for an input at any one time. A multi-touch input is not allowable, which restricts the application of the conventional touch panel.